The following U.S. patents are incorporated herein by reference in entirety.
U.S. Pat. No. 5,205,110 discloses an indexing motion apparatus and method for vacuum packaging of articles such as hot dogs, sliced luncheon meat, cheese or pharmaceuticals. A lower web of packaging material is indexingly advanced by a lower web drive driven in an indexing manner by a servo motor. Forming tooling is provided for vacuum forming the lower web to form one or more product cavities and the forming tooling is movable between raised and lowered positions by a lifting and lowering system driven by a servo motor. After the formed product cavities are loaded with product, the cavities are evacuated and an upper web applied to vacuum package the product. A slitting mechanism severs the upper and lower webs into individual product packages. The servo motors are programmable and provide accurate position of the components of the packaging machine, and also provide ease in changing the various parameters of the packaging machine according to the type of product being packaged.
U.S. Pat. No. 8,186,134 discloses packaging machines that include a web transport conveyor for transporting a web of flexible packaging material from upstream to downstream locations through a series of stations and packaging apparatuses. A forming station and a closing station each have movable die members that are counterbalanced.
U.S. Pat. No. 8,499,536 discloses packaging machines that include a web transport conveyor transporting a web of flexible packaging material from upstream to downstream locations through a series of stations.